September 14, 1888. J 



SCrENCE. 



129 



iron tubes, bedded in concrete. There are water-tight man-holes at 

 intervals. The electric wires are drawn into the tubes, and the 

 circuits for the lamps, etc., are taken off at the man-holes. Conduits 

 constructed in this manner seem perfectly water-tight. 



There are in New York to-day 420 miles of single duct, contain- 

 ing some 4,000 miles of telephone and telegraph wire, and some 

 hundreds of miles of incandescent electric-light conductors. The 

 conduits for high-potential wires are separated from those for tele- 

 phone and telegraph wires. Up to the present, no arc-lighting 

 company has put its wires under ground, but the 15rush Electric 

 Company is going to draw wires into the conduit between 14th and 

 34th Streets. 



Mr. Wheeler then spoke of the present condition of electric cir- 

 cuits in New York, and ijointed out the danger of the great num- 

 ber of ' dead wires,' — wires abandoned by the users, and allowed 

 to remain because of the expense of taking them down. These 

 come in contact with electric-light wires, and are a source of dan- 

 ger. 



Summing up, Mr. Wheeler stated that the telegrai5h and tele- 

 phone problems were practically solved ; 4,000 miles of their wires 

 were already under ground, and 12,000 more were to go this fall. 

 The saving in the cost of maintenance is estimated at §100,000 

 per year. The laying of electric-light wires is not so fully devel- 

 oped ; but when the initiative is once taken, the difficulties will be 

 overcome and the undergrounding will become a settled and accom- 

 plished fact. 



Dr. P. H. Van Der Weyde's paper on ' The Comparative Dan- 

 ger of Alternating vs. Direct Current,' is a criticism on the experi- 

 ments of Mr. H. P. Brown on the danger of alternating currents, 

 which were described and commented on in the last number of 

 Science. It is mainly an attack on Mr. Brown's methods of meas- 

 urement, and it betrays want of acquaintance with Ohm's law 

 and Cardew's voltmeter. " After the lecture I examined the volt- 

 meter, and found, that, according to the statements of Mr. Brown 

 himself, its operation was based upon indications of rise in temper- 

 ature. Now, it is well known that voltmeters based on this prin- 

 ciple are based on false premises; rise of temperature is not pro- 

 duced by electro-motive force, but by amount of current. . . . This 

 is so self-evident that Prof. G. Forbes from England, who last year 

 exhibited . . . a meter for alternating currents, did not think of call- 

 ing it a voltmeter, because its operation was based on rise of tem- 

 perature, but he called it a current-meter." Dr. Van Der Weyde's 

 suggestion for measuring the voltage of the current used possesses 

 the charm of novelty. " In order to come to correct conclusions, it 

 would be necessary to measure, by means of indicator-diagrams, 

 the engine-power utilized, and measure the currents obtained by 

 proper instruments, properly used and conscientiously observed." 

 After this is done, the volts are to be calculated by dividing the 

 energy calculated from the indicator-diagrams by the number of 

 ampferes. 



The paper, in fact, is of the type that brought the ridicule on the 

 association at its early meetings, of which the president complained 

 in his address. 



The other papers read will be given in a later issue. 



SCIENTIFIC NEWS IN WASHINGTON. 

 The Army Medical Museum : a Great Object-Lesson for Thoiie who 

 understand its Purpose and System of Arrangement : Interesting 

 Subsidiarj' Work. — An International Marine Congress : an Impor- 

 tant Plan of the United Slates Hydrographic Ollice to be carried 

 into Operation. — Disinfectants that destroy the Germicidal Power 

 of Each Oilier. 



The Army Medical Museum. 



Of the thousands of people who visit the Army Medical Muse- 

 um every year, not one per cent, probably, have any clear con- 

 ception of the object aimed at in gathering and exhibiting a collec- 

 tion of what to most people are disgusting objects. They look 

 upon the museum as a sort of chamber of horrors, placed there for 

 the purpose of giving people an opportunity to gratify a rather de- 

 praved curiosity. 



But to those who understand that the museum is a great, syste- 

 matically arranged object-lesson, in which the physical history of 



man in health and in disease, and at all stages of development, is 

 given and illustrated, it becomes no longer a place in which to grat- 

 ify a morbid curiosity, but one in which to pursue, under the most 

 favorable circumstances, one of the most fascinating of studies. 



The Army Medical Museum, which for many years was housed 

 in the old Ford's Theatre building, the scene of President Lincoln's 

 assassination, was removed last spring from its contracted and in- 

 convenient quarters to a line new building erected especially for its 

 use and for the accommodation of the medical library. It is near 

 the Smithsonian Institution and National Museum. A smaller 

 building, to be used as a biological laboratory, has since been 

 added, so detached from the main building and so scientifically and 

 thoroughly ventilated as to make it impossible for gases or odors to 

 pass from it into the main building or into the surrounding air. 

 Congress has not yet made an appropriation to pay for fitting up 

 this laboratory, but is expected to do so in one of the bills now 

 pending. 



The museum itself is provided with a large, airy, and well-lighted 

 e-\hibition-hall in the second story of the new building. There is 

 plenty of room to accommodate it for many years to come, although 

 it is at present receiving accessions at the rapid rate of more than 

 five hundred specimens a year, and is now one of the ten largest 

 medical museums in the world. The aggregate amount of money 

 appropriated by Congress for the museum itself, aside from the 

 cost of the building, has been only about fifty thousand dollars. 

 Several of the great museums of Europe have been in existence 

 since the last century, and the great museum in London began 

 with a collection for which one hundred thousand dollars was paid. 

 In consideration of the short time since the museum in Washing- 

 ton was established, and the small amount of money spent upon 

 it, the results are very highly creditable to Dr. Billings, who has 

 charge of it. 



In arranging the objects in the museum, the embryology of man 

 as a complete individual in health is first illustrated. The speci- 

 mens in this department are numerous and very interesting. The 

 embryology of the lower animals is also shown, as far as it throws 

 light upon that of man, but Dr. Billings does not enter deeply into 

 the illustration of the comparative embryology of the lower animals, 

 as that falls not within his province, but in that of the National 

 Museum. 



The next step in illustrating the physical history of man is to 

 divide the body into its several parts, and to treat each separately. 

 For instance, the head is first presented in its healthy state. This 

 is shown in all stages of development, from its first appearance in 

 the embryo, with its gradual growth and the appearance of new 

 organs, to its state of development at the period of birth, — in 

 childhood, youth, maturity, and old age. Not only is the head as a 

 whole shown, but the separate organs are also presented in every 

 form, at all ages, and in all their varying conditions. Here, also, 

 corresponding portions of the lower animals are shown, but, as in 

 the former instance, only so far as they illustrate, and assist in 

 understanding, the organs and functions of that particular organ of 

 the human body. Every part of the body is treated in the same 

 systematic way. There is also a case showing remarkable mon- 

 strosities in man and animals. 



Having treated and shown the body as a whole in its embryology 

 and its anatomy, and all the parts separately, in its healthy, nor- 

 mal conditions, the next series of cases shows the body in dis- 

 ease. The system of treatment is the same as that adopted in 

 illustrating the body in health. Beginning with the body as a 

 whole, in its earliest embryo state, and showing by actual speci- 

 mens the effect of all diseases to which it is subject, its different 

 great divisions are shown in all known conditions of disease, from 

 the head, when it first appears in the embryo, through all its his- 

 tory, and in all its separate organs, and in every morbid condition 

 to which its various parts and organs are subject, to the lower ex- 

 tremities. Thus the organ and its several parts are shown through 

 their entire life-history whenever modified by disease. The entire 

 series, therefore, includes a representation, by actual anatomical 

 specimens, of the effect of disease upon every organ of the body. 

 By the side of the diseased organs affected by bacteria that have 

 been identified by biological research, such as typhoid- fever, diph- 

 theria, cholera, yellow-fever etc.. it is proposed to place the cul- 



